In an LTE (Long Term Evolution) system and an LTE-A (Long Term Evolution-Advanced) system, a phenomenon of intra-frequency networking usually occurs. In this case, downlink interference may exist between neighboring cells in a system. In particular, in a heterogeneous network and a small-cell network, this problem may be severer. Specifically, when downlink interference exists on a PDSCH (Physical Downlink Shared Channel), downlink throughputs of a user terminal and a system are severely affected.
Specifically, the following manners are generally used in the industry currently to resolve the foregoing downlink interference problem.
Manner 1: An ABS (Almost Blank Subframe) manner is used to reduce downlink interference. Specifically, a network-side device such as a base station may set some time periods of a cell, for example, a subframe, as an ABS subframe. In a position of the ABS subframe, the cell basically does not transmit any downlink signal, so that interference caused in the position of the ABS subframe by the cell to a neighboring cell is greatly reduced, and that an effect of increasing a downlink throughput of the neighboring cell may be achieved.
Manner 2: A network-side device such as a base station may transmit an interference cancellation parameter such as a CRS (Cell-specific Reference Signal)-related parameter and/or a PDSCH-related parameter of a neighboring cell to a user terminal, so that the user terminal cancels, according to the interference cancellation parameter, interference caused by the CRS-related parameter and/or PDSCH-related parameter of the neighboring cell to downlink data.
However, when the manner 1 is used to cancel downlink interference, a specified cell basically does not transmit any downlink signal in some time periods, that is, the manner 1 is to obtain relatively weak downlink interference by sacrificing some communication resources of the specified cell, and therefore, utilization of downlink spectrum resources of the specified cell is reduced to some extent. When the manner 2 is used to cancel downlink interference, an interference cancellation effect of the user terminal may be impaired because currently there is no specification on how the user terminal should process a previously received interference cancellation parameter when the user terminal needs to perform an operation such as cell reestablishment or cell handover due to radio link failure or handover of the user terminal.
That is, when the existing interference cancellation manners are used to perform interference cancellation, an interference cancellation effect achieved is poor. Therefore, it is urgent to provide a new interference cancellation manner to resolve the foregoing problems.